If I have Grisha right, what he is saying is that it takes so many minutes to earn enough to buy a loaf of bread. In that context it matters not a jot whether you earn $10 in that time and the loaf costs $10, or whether you earn $1 and the loaf costs $1. When economists talk about inflation they are normally concerned with the $1 or $10 figure. What matters for day-to-day purchasing is the 'time required to buy a loaf'. The economists inflation does matter to us lesser mortals as well, but more in terms of debts and savings, not day-to-day living.